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Shane's Knobs


Moonshane
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Hi all

After seeing the excellent Bob's Knobs on everyones newts and cats, I contacted Bob and although he was amazingly helpful he did not unfortunately have an off the shelf solution for my secondary adjusters. The reason for this (ironically) is that my secondary is a non-standard but better quality than usual unit from USA which has adjusters with an imperial thread rather than a metric one.

Therefore I set about making some for myself. I ordered some UNC 10-24 threaded road (stainless) and just today after several aborted attempts, managed to find some suitable knobs from a local hardware store who had a box of odds and sods. These are apparently something to do with old fuse boxes. Made of bakelite or similar and with a brass centre they were perfect.

I drilled out the existing thread to about 4.5mm and this was now a perfect fit for the threaded rod.

Using some two pack epoxy resin glue I then inserted the rod into the knobs and left them to dry.

They seem spot on and once the glue goes off I'll add them to the scope. They will make my collimation even easier each session as I will not have to fish around in the dark at the bottom of a 60mm hole to find the grab screw socket for the allen key.

Here's some pics - I'll upload another once they are fitted to the scope. I reckon that anyone can make these with a drill a hacksaw and some glue. Just take one of your adjusting screws out, measure the length you need and take it to a hardware shop - you may even have screws/bolts of a suitable thread in your shed and you could even use a short piece of wooden dowel for your 'caps'.

Cheers

Shane

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Edited by Moonshane
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ha ha - so well put.

I like a challenge for sure but when I knew it would not be straight forward getting some my tightwad shoulder demon kicked in and started whispering in my shell like.

that said, it probably cost me about the same as buying some as a set of Bob's!!

the other thing I realised a while back was that the threads on the primary adjusters (which were wing nuts) was standard M6. I therefore got some threaded rod connectors too and they work a treat. see below

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indeedy. I'd probably add, and being a tightwad is it's Uncle.

in fact I have just notice the disparity in my primary adjusters. I wonder if my secondary is too far down the tube? might just be that one spring has more spring in it than the others and when I tightened them all to back them off a turn that may explain it. it looked OK the last time I checked through the colli cap.

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hi all

the glue's gone off properly and I fitted my 'Shane's Knobs' to my dob. They work a treat and make it far less fiddly to adjust the secondary now. I might just touch them with matt black paint as they are quite shiny but don't think it'll make that much difference really. any thoughts? (about the reflections I mean)

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Are they tucked in behind the secondary mount?

yeah, I thought about that too - the shroud around / the secondary is just a bit wider than the spider centre so they are just out of the 'light train', you can just about see this in the pic if you squint :D

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